Answer:
v = 10 [m/s].
Explanation:
The largest mass is that of 4 [kg], in this way the momentum can be calculated by means of the product of the mass by velocity.

where:
P = momentum [kg*m/s]
m = mass = 4 [kg]
v = velocity = 5 [m/s]
Now the momentum:
![P=4*5\\P=20[kg*m/s]](https://tex.z-dn.net/?f=P%3D4%2A5%5C%5CP%3D20%5Bkg%2Am%2Fs%5D)
This same momentum is equal for the other mass, in this way we can find the velocity.
![P=m*v\\20=2*v\\v=10[m/s]](https://tex.z-dn.net/?f=P%3Dm%2Av%5C%5C20%3D2%2Av%5C%5Cv%3D10%5Bm%2Fs%5D)
Answer: B
Action and reaction forces act on the same object and go to the same direction
Given that,
Mass of object, m = 55 kg
Mechanical energy of the object, M = 4306 J
Potential energy, P = 2940 J
We know that the mechanical energy is the sum of kinetic and potential energy such that,
Mechanical energy = kinetic energy + potential energy

Kinetic energy is given by :
v is velocity of object

So, the velocity of object is 7.04 m/s.
You want to know how to solve it?
A. Velocity///////////////////